Knowledge base for software setup, errors, and daily tool work.

Git Push Rejected Non Fast Forward: Troubleshooting Checklist

Fix Nginx 'Permission Denied' Upstream Errors

When Nginx logs permission denied while connecting to an upstream (e.g., a Unix sock...

Fix ERR_CONNECTION_RESET Caused by Chrome Extensions

If you see the ERR_CONNECTION_RESET error in Chrome, it often means a network connection was inte...

Fixing Cloudflare 521 Error: Origin Unreachable

When you see Cloudflare error 521, it means your origin server is refusing the connection from Cl...

Nginx Upstream Connection Refused: Diagnosis and Fixes

When Nginx returns a 502 Bad Gateway or logs "upstream connection refused", it means Ngin...

Fix Windows Update Error 0x80070005 Using Command Prompt

Windows Update error 0x80070005 typically indicates an access denied problem. This often happens ...